These recordings were made with a high
resolution studio quality digital recording system. The microphone was 3" from
the edge of the PSU exhaust grill at a 45° angle to
avoid direct wind noise. The ambient noise during all recordings was 18 dBA or
lower.

To set the volume to a realistic level (similar to the original), try playing the Nexus 92 fan reference recording and setting the volume so that it is barely audible. Then don't reset the volume and play the other sound files. Of course, tone controls or other effects should all be turned off or set to neutral. For full details on how to calibrate your sound system to get the most
valid listening comparison, please see the yellow text box entitled Listen to
the Fanson page four of the article SPCR's Test / Sound Lab: A Short Tour.

CONCLUSIONS

With enough care and effort, the NX-9003 could probably be put to good use
in a quiet system. That system would need to draw very little power in idle
to ensure that the cooling fan does not cycle on and off. At the same time, the power
draw under load would need to be high enough that the fan stays on once it
comes on. For most people, the fan controller will just be too much trouble
to work with; there are many other quieter PSU alternatives.

True, its voltage regulation is excellent. But it's not especially efficient, it
isn't especially well-cooled, and it is too expensive for a power supply that doesn't
come out on top in at least one category. The thing that
distinguishes the NX-9003 from the competition is its ability to turn off its
cooling fan and any other fans that are attached to it. However, this ability is too
poorly implemented to be beneficial.

Ultimately, the NX-9003 is an interesting failure.
In our view, the fan controller needs a lot more work before we can recommend this PSU for quiet seekers.

When a user turns on their computer, the sensor of the NX-9003 SFB will detect the system fan and check whether the two system fans are there or not.

If user doesn't connect system fans before the computer is booted, the sensor will give PSU a sign which is not to provide load to system fan. However, the load is not 0 V.

Thats why 1.9V was detected in the review. If the system fan is connected while the computer is on, the system fan will not run. So, the key point is that the system fan should be connected before the computer is booted.